1. Field of the Invention
The present invention relates to an imaging apparatus having at least one bending optical element, and in particular relates to such an imaging apparatus which is small in size and equipped with an inclination adjusting mechanism for adjusting the inclination of an image sensor.
2. Description of the Related Art
In recent years, mobile electronic devices which are designed mainly for taking still/moving photographic images, such as digital cameras (still-video cameras) and digital camcorders (motion-video cameras), and other mobile electronic devices which are designed to be capable of taking such photographic images as a subsidiary function, such as mobile phones equipped with a camera and tablet computers, etc., equipped with a camera, have become widespread, and there has been a demand to miniaturize the imaging units incorporated in these types of mobile electronic devices. In order to miniaturize an imaging unit, it is known to configure an optical system of an imaging unit as a bending optical system which reflects (bends) a light bundle using a reflection surface of a reflecting element (bending optical element) such as a prism or a mirror. An imaging optical system having at least one bending optical element (hereinafter also referred to as the “imaging apparatus”) is advantageous in achieving a reduction in thickness of the imaging unit, especially in the travelling direction of the incident light emanating from an object to be photographed.
In such an imaging apparatus, an image sensor (image pickup device) is arranged on a post-bending optical axis (the optical axis after being optically bent by a bending optical element). Usually the image sensor is fixed to an image sensor board (image-sensor mounting board) that is provided as a separate member from the image sensor, and this image sensor board is fixed to a housing which supports an imaging optical system (which includes lens groups and at least one prism). An adjusting mechanism for adjusting the inclination of such an image sensor relative to a plane orthogonal to an optical axis is known in the art and disclosed in, e.g., Japanese Unexamined Patent Publication No. 2006-293187. However, this adjusting mechanism is unsuitable for achieving a reduction in thickness (slimming down) of the imaging unit.
Further examples of the related art are also disclosed in Japanese Unexamined Patent Publication Nos. 2006-267391, 2010-243763, and 2013-105049.